1. Field of the Invention
This invention relates generally to the field of computer graphics and, more particularly, to software for rendering graphics data.
2. Description of the Related Art
As the pervasiveness of computers increases, the amount of information that applications and users need to display has also increased. The problem of displaying ever increasing amounts of information is exacerbated by the recent trend toward smaller displays. For example, personal digital assistants are becoming more popular because of their portability. However, this portability tends to require smaller displays. Thus, system designers are facing the difficult task of having to display increasing amounts of information on smaller screens.
Desktop personal computers and workstations are facing similar problems. With the processing power now available, it is possible to simultaneously run a large number of applications, each having multiples windows and/or documents open at the same time. Applications routinely manipulate very large databases of information, and the results tend to overflow current displays. Thus, even with increases in desktop screen size, displays are becoming even more crowded.
One common technique currently in use that allows a particular screen size or window to display more information is called “scrolling” or “zooming”. In scrolling, the window displays only a portion of the entire image, and the user is able to shift which portion of the entire image is shown in the current window. In zooming, a portion of the image being displayed is magnified (usually to show more detail) at the expense of displaying other portions of the image. Scrolling and zooming are often combined to create an effective user interface. For example, mapping software may display a detailed map of an eastern section of a city. The user may “zoom out” to display the entire city (at a lower level of detail), scroll over to the western section of the city, and then “zoom in” on a final destination to see more detail.
Techniques such as scrolling and zooming have increased the amount of information that may be accessed using a given screen size. However, these techniques may not go far enough to allow large amounts of data to be viewed on a given screen size. Another class of techniques that attempt to address this problem allow users to vary non-positional (i.e., non-spatial) display attributes such as transparency and size. However, these techniques can be inefficient and sometimes distracting. Particularly when an object is drawn as small, highly transparent, or in an otherwise non-prominent state, it can be both computationally inefficient and a potential distraction to the user to create a highly detailed rendering of the object.
For at least these reasons, a system and method for efficiently displaying information on a computer display is desired.